Field of the Disclosure
The present disclosure, for example, relates to wireless communication systems, and more particularly to using known geographical information in directional wireless communications.
Description of Related Art
Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems.
By way of example, a wireless multiple-access communication system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, otherwise known as user equipments (UEs). A base station may communicate with UEs on downlink (DL) channels (e.g., for transmissions from a base station to a UE) and uplink (UL) channels (e.g., for transmissions from a UE to a base station).
A wireless multiple-access communication system may use any of a number of different frequency bands depending on the particular needs of the system. For example, in some systems, a large number of UEs may be located relatively close to one another (e.g., in a public transportation passenger train). The millimeter wave frequency band (which may be 20 to 300 GHz) may be used in these situations with a concentration of UEs because of the relatively large amount of bandwidth that is available in this frequency band. Millimeter waves, however, frequently experience high path loss, and as a result, directional beam forming techniques may be used for UL and/or DL transmissions between a base station and a UE.
In order to utilize directional beam forming, the base station and/or the UE may need to search for and track the desired beam direction. Searching and tracking the desired beam direction over an entire 360-degree field, however, can consume large amounts of frequency and time resources.